1. Field of the Invention
The invention relates to the design and structure of electrical connectors. More specifically, the invention relates to connector back shell designs having the ability to provide a number of cable exit angles and cable strain relief with a single set of components.
2. Description of the Related Art
A back shell is a device used in wire interconnect assemblies to transition from a plurality of insulated conductors (a plurality of wires or cable) to an electrical connector. The electrical connector will have conductive devices, usually in the form of pins or sockets, to which each of the conductors from the cable is terminated. The pins or sockets are held in a specific geometric arrangement within the shell of the connector, in order to mate with a matching connector having a similar arrangement of conductive pins or sockets. The wire from each of the conductors in the cable is attached to the pins or sockets in the electrical connector via soldering, crimping, or welding. These means of attachment can be subject to breakage if stresses from the wire cable are transmitted to the attachment points. In most cases, the back shell will provide some means for securing the wires or cable such that any forces acting upon the wires or cable will not be imposed on the wire connections and at the end of the wires. This is referred to as “strain relief” and is an important function performed by the back shell. In many cases this function is performed by either saddle clamps or banding platforms to accommodate either metallic or plastic bands. Another important function of the back shell is to direct the wire cable in a particular direction as it exits the connector. Typically, this is done with a short section of hollow conduit through which the cable is inserted. These are often manufactured with a fixed orientation such as straight (0 degrees), 45 degrees, or 90 degrees, and are an integral part of the back shell construction.
One problem experienced by connector users is that once a cable is terminated into a particular connector and back shell orientation, changing that orientation during assembly in the field can be difficult. Even if the connector design allows multiple back shell orientations to be utilized without re-terminating the cable, the user still has to purchase and stock many back shell components for this purpose, which can be expensive. It would be desirable to have a back shell design that allows a plurality of cable exit angles with a single set of components that are an integral part of the back shell.
One such design is currently available which incorporates a means to overcome this problem. U.S. Pat. No. 6,419,519 discloses a design where the wire securing mechanism is at the end of dual arms that swing or pivot to adjust to different angular increments. Hardware then secures the assembly in place. Whilst this method meets the requirement of being able to accommodate multiple orientations of wire containment with a single back shell, it is burdened with multiple screws and hardware components, each requiring adjustment, and each having the ability to come loose becoming FOD (Foreign Object Debris) in high stress and/or critical applications. The design is also complex, and adjustment of cable direction may be difficult if the connector is terminated and there is no access to all the adjustment mechanisms.
What is needed is a more reliable, simple back shell design that provides appropriate strain relief while allowing a plurality of cable exit angles with a single set of components integrated into the back shell.